Kentucky

Statewide summary — confirm with your building department before designing

Two values were corrected by this audit. Ultimate design wind speed corrected from 105 to 115 mph: the Kentucky Residential Code fixes Vult at 115 mph for all Kentucky counties statewide, which governs over the ASCE 7-16 map (site values across Kentucky interpolate to about 105 to 106 mph). Seismic design category corrected from A to C: no Kentucky location is SDC A under ASCE 7-16 at Site Class D and Risk Category II. Louisville is C and Lexington B; Owensboro, Hopkinsville and Bowling Green are D; and far western Kentucky is much higher, with Paducah and Fulton at D1 and Hickman in the New Madrid zone at E. The Kentucky code does not fix a statewide seismic category and requires a site-specific determination, so C is published only as the value governing the largest metropolitan area. Do not use it in the Jackson Purchase. The remaining values are confirmed by the state code and were not changed: frost depth 24 inches is the statewide minimum in Table R403.1.4, with nineteen named eastern and northern counties at 27 to 33 inches; ground snow load 15 psf is the Jefferson County value, with northern and eastern counties at 20 psf and elevations above 2500 to 2600 feet requiring site-specific study. Termite infestation probability is moderate to heavy for all Kentucky counties per the state code; the stored value heavy sits inside that band. The winter design temperature is ASHRAE data, is not set by the Kentucky code, and is unverified. 2026-08-12 snow-load audit. Kentucky is one of the few states that publishes a genuine statewide ground snow load table, so a real min and max exist here. Table R301.2(1) of the 2018 Kentucky Residential Code, Third Edition (August 2024), adopted under 815 KAR 7:125, lists a ground snow load pg for each of the 120 Kentucky counties. Every county is either 15 or 20 psf; there is no third value. Minimum 15 psf and maximum 20 psf are now recorded. The eighteen counties at 20 psf are Boone, Boyd, Bracken, Campbell, Carroll, Floyd, Gallatin, Grant, Greenup, Henry, Kenton, Knott, Leslie, Letcher, Lewis, Martin, Mason and Trimble; the other 102 are 15 psf. Three counties carry an elevation footnote that withdraws the tabulated number rather than raising it: in Bell and Harlan above 2600 feet, and in Letcher above 2500 feet, the code requires the ground snow load to be set by site-specific case study or other approved rational analysis. The recorded maximum of 20 psf is therefore the highest figure the state actually tabulates, not a ceiling; high-elevation sites in those three counties can exceed it and the code deliberately declines to say by how much. Seismic design category corrected from C to B, which reverses part of the previous audit, because two official sources conflict. The Kentucky Residential Code publishes its own county-by-county Table R301.2.2.1, and that table assigns Jefferson County, and therefore Louisville, category B. The USGS ASCE 7-16 design-maps service computed at Site Class D and Risk Category II puts Louisville in category C, which is the figure the previous audit recorded. Both are recorded here. The state table is the value used, because it is the legally binding number a Kentucky building official enforces under KRS 198B, whereas the USGS service is a hazard reference that the Kentucky code does not incorporate for assigning this category. The adopted table spans A to D2: Boone, Campbell and Kenton are A; 89 counties are B; 14 are C; Caldwell, Crittenden, Lyon, Trigg and Union are D0; Calloway, Livingston and Marshall are D1; and Ballard, Carlisle, Fulton, Graves, Hickman and McCracken are D2. No Kentucky county is tabulated at E, which also corrects the earlier note's statement that Hickman is E. A single statewide seismic category remains a fiction and Jackson Purchase sites must use their own tabulated value. Two stored values were re-verified against the current Third Edition and confirmed unchanged. Table R301.2(1) states that the basic ultimate wind speed Vult shall be 115 mph for all Kentucky counties, confirming the stored 115. Table R403.1.4 sets minimum frost protection depth at 24 inches for all Kentucky counties except fifteen named eastern and northern counties at 27 to 33 inches, confirming the stored 24 as the statewide baseline. The stored ground snow load of 15 psf is confirmed as both the Jefferson County value and the value for 102 of the 120 counties.